PSEUDOTRICHIA RUBIGINOSA (PULMONATA, HYGROMIINAE): A SNAIL NEW TO FRANCE

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1 JOURNAL OF CONCHOLOGY (2004), VOL.38, NO PSEUDOTRICHIA RUBIGINOSA (PULMONATA, HYGROMIINAE): A SNAIL NEW TO FRANCE X. CUCHERAT & S. DEMUYNCK 1 Abstract Pseudotrichia rubiginosa is recorded for the first time in the North of France in July 2001 in the valley of the Lys river. Its habitat and malacological community are described. The results are compared with the available ecological data on this species in Western Europe. Key words Pseudotrichia rubiginosa, Lys river, France. INTRODUCTION The first record of Pseudotrichia rubiginosa (Rossmässler, 1838), made by Clanzig (1987), in the Mont Pilat (Loire), was recently disproved by Falkner, Ripken & Falkner (2002) in their checklist of the non-marine molluscs of France. These authors contested the presence of this species in a mountain context since Pseudotrichia rubiginosa had only been reported from flooded river plains. This snail lives in wetlands in the flood zone of freshwater rivers. The habitat is characterized by areas of bare mud, covered with an important layer of litter and by a sparse community of tall herbs often including nitrophilous plants species (Obrdlik, Falkner & Castella, 1995; Killeen, 1999). Pseudotrichia rubiginosa is an East-European species (Kerney, Cameron & Bertrand, 1999), which is listed in the British Red Data Book (Bratton, 1991) under Category RDB2, Vulnerable, and is also listed in the German Red List (Falkner, 1990). In the western part of its distribution range, Pseudotrichia rubiginosa is present in Belgium in the Scheldt valley and its tributaries (Vader, 1977; De Wilde, Marquet & Van Goethem, 1986; Van Goethem, 1988) and in Britain in the Thames valley (Naggs, 1983; Killeen, 1999). Given this geographical distribution, it was considered that surveys for the species in northern France were merited. Figure 1 a-b specimen of Pseudotrichia rubiginosa from Nieppe, River Lys (Actual shell diameter 6 mm). 1 Université des Sciences et Technologies de Lille, Laboratoire d Ecologie Numérique et d Ecotoxicologie. FR CNRS Bât. SN3, F Villeneuve d Ascq Cedex. xavier.cucherat@wanadoo.fr

2 320 X. CUCHERAT & S. DEMUYNCK Figure 2 Pseudotrichia rubiginosa dart from Nieppe, River Lys (scale bar 100 µm). DESCRIPTION EXTERNAL FEATURES The following description of Pseudotrichia rubiginosa has been compiled from the accounts of Falkner (1990) and Kerney et al. (1999). The shell is globular with a convex spire, slightly tumid whorls separated by shallow sutures. The last whorl is not angulated at the periphery. The aperture, without internal rib, is rounded with a non-complete peristome. Lip is sharp and reflected over columella, leaving a narrow umbilicus. The shell is red-brown, thin, translucent and moderately glossy. The periostracum is densely haired with short and moderately bent hairs at their extremity. When the shell is old, hairs are often absent. The head, the tentacles and the back of the animal are grey-anthracite; the foot and lateral parts of the body are whitish-grey. The mantelcollar is a pinkyred colour (see Fig. 1 a-b). INTERNAL FEATURES The male part of genitalia is composed of long and thin penis sheath and epiphallus. The flagellum is also long and thin (flagellum is about 1 2 penis sheath plus epiphallus). The vagina possesses a lateral and long dart sac. The dart is curved and twisted (see Fig. 2). There are two pairs of mucus glands, which are long and narrow. LOCATION AND DESCRIPTION OF THE STATION Pseudotrichia rubiginosa was discovered in July 2001 in the Lys valley (tributaries of the Scheldt river), in the municipality of Nieppe (Nord; DS 81), 20 km W of Lille. The site comprises about a 100 m length of the Lys river, between a meadow and an open field. The site is adjacent to a ditch which separates it from the meadow. This ditch periodically floods the site. The floristic assemblage is given in Table 1. This assemblage shows that the station is occupied by a tall herb community dominated by the sedge Carex riparia (spatial extension comprised between 50 and 75% of the total surface) changing to a sedge fen (De Foucault, personal communication). The other plants species are all associated with wetlands. The other species of molluscs collected with Pseudotrichia rubiginosa are given in Table 2. It can be seen that nine species are hygrophilous land snails but three of them were recorded only as very old shells. The occurrence of two freshwater snails (Galba truncatula and Anisus cf. spirorbis), found as empty shells, indicates that the site is sometimes flooded by the ditch.

3 PSEUDOTRICHIA RUBIGINOSA IN FRANCE 321 TABLE 1 The floristic assemblage of the station containing the land snail Pseudotrichia rubiginosa Plant species Spatial extension in % Caltha palustris L Calystegia sepium (L.) R. Brown. Carex riparia Curt. Equisetum palustre L. Filipendula ulmaria (L.) Maxim. Phragmites australis (Cav.) Stend. Symphytum officinale L TABLE 2 List of the molluscs associated with Pseudotrichia rubiginosa at the site of Nieppe Species Galba truncatula (O.F Müller 1774) Anisus cf. spirorbis (Rossmässler, 1835) Carychium minimum O.F Müller 1774 Succinella oblonga (Draparnaud, 1801) Succinea putris (Linnaeus, 1758) Cochlicopa sp. Vallonia pulchella (O.F Müller 1774) Vertigo pygmaea (Draparnaud, 1801) Vitrea crystallina (O.F Müller 1774) Nesovitrea hammonis (Ström, 1765) Deroceras laeve (O.F Müller 1774) State Dead shells Dead shells Sub fossil Sub fossil Sub fossil DISCUSSION Pseudotrichia rubiginosa is also known as Perforatella rubiginosa (e.g. Killeen, 1999). In accordance with Falkner (1993) and the Check-list of the Continental European Mollusca (CLECOM) (Falkner, Bank & Von Proschwitz, 2001), we prefer to use Pseudotrichia rubiginosa. This is the first time that Pseudotrichia rubiginosa has been recorded in France, and in a similar habitat as those previously described from Western Europe (Vader, 1977; Killeen, 1999). In fact, the station of Nieppe shares a lot of common features with the sites of the region of the Scheldt estuary in Belgium described by Vader (1977) or those in the Thames valley described by Killeen (1999). These features are: the temporary presence of the water, the importance of decaying organic rich litter, the muddy consistency of

4 322 X. CUCHERAT & S. DEMUYNCK the sediment and the presence of nitrophilous plant species. The occurrence of dead shells of freshwater gastropods proves that the place is often flooded by the ditch, although the Nieppe station is not a freshwater tidal flat as it is the case for most sites where Pseudotrichia rubiginosa occurs in Western Europe (Vader, 1977; Killeen, 1999). In addition, the soil seems to retain a high percentage of humidity since most of the species found together with Pseudotrichia rubiginosa are hygrophilous land snails. The litter is produced in situ, unlike in the Thames valley (Killeen, 1999) or in the Scheldt valley (Vader, 1977) where it comprises flood debris deposited by rivers. This litter is mainly composed of leaves of Carex riparia and Phragmites australis. Finally, the plant community although dominated by Carex riparia contains nitrophilous species ones such as Symphytum officinale. To conclude, the uncommon place of this record, next to a ditch, allows us to think that the main requirements of this snail are the soil humidity level and the amount of organic matter. Additional studies are now in progress to investigate this hypothesis. ACKNOWLEDGEMENTS This work was supported by funds from DIREN (Regional Department of Environment of Nord/Pas-de-Calais) which is gratefully acknowledged. Dr. Alain Leprêtre (Laboratory of Numerical Ecology and Ecotoxicology of University of Lille) and one anonymous referee kindly reviewed and improved the manuscript. We also thank Bruno de Foucault (Faculty of Pharmacology of Lille) for the floristic relevé. We are indebted to Gerhard and Margrit Falkner for their help in identification and for having encouraged us to write this article. REFERENCES BRATTON J.H. (ed) 1991 British Red Data Books: 3. Invertebrates other than insects JNCC, Peterborough. CLANZIG S Limaces et escargots du Parc Naturel Régional du Pilat Xenophora 36/37: DE WILDE J.J., MARQUET R. & VAN GOETHEM J.L Atlas provisoire des Gastéropodes terrestres de la Belgique Institut Royal des Sciences Naturelles de Belgique, Bruxelles, 285pp. FALKNER G Binnenmollusken In R. Fechter & G. Falkner Weichtiere Mosaïk Verlag, München. FALKNER G Zur nomenklatorischen Problematik von Helix rubiginosa Rossmässler, 1838 Heldia 2: FALKNER G., BANK R.A. & VON PROSCHWITZ T Checklist of the non-marine Molluscan Speciesgroup taxa of the State of Northern, Atlantic and Central Europe (CLECOM I) Heldia 4 (1/2): FALKNER G., RIPKEN E.J. & FALKNER M Mollusques continentaux de France: liste annotée et bibliographie Patrimoine Naturel 52: 370pp. KERNEY M.P., CAMERON R.A.D. & BERTRAND A Guide des escargots et limaces d Europe Delachaux & Niestlé, Lausanne-Paris, 370pp. KILLEEN I.J Distribution and conservation of Perforatella rubiginosa (Pulmonata: Helicidae) in Britain Journal of Conchology 36: NAGGS F Perforatella: the helicid snail newly recorded in Britain and other genera commonly confused with Trichia Journal of Conchology 31: OBRDLIK P., FALKNER G. & CASTELLA E Biodiversity of Gastropoda in European floodplains

5 PSEUDOTRICHIA RUBIGINOSA IN FRANCE 323 Archiv für Hydrobiologie Supplement 101 Large Rivers 9: VADER W Habitat and distribution of Perforatella rubiginosa (Gastropoda, Pulmonata) in freshwater tidal region of the Scheldt estuary, Belgium Hydrobiologia 52: VAN GOETHEM J.L Nouvelle liste commentée des mollusques récents non-marins de Belgique Document de travail de l Institut Royal des Sciences Naturelles de Belgique, Bruxelles, 69pp.

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